This program explores a research theme in cell biology: the interactions of microtubules and microfilaments of the eukaryotic cell cytoskeleton with the cell membrane. It consists of several subprojects: 1. Antagonistic Actions in Cytoskeletal Membrane Controls; 2. Analysis of Membrane Components and Changes; 3. Cell Structure and Membrane Permeability; 4. Cytoskeleton and Renal Tubular Function. These explore central questions of the determination of cell shape, organelle distribution and movement, the mitogenic stimulus and membrane biogenesis in interrelated fashion. Current problems include examination of the role of calmodulin in ciliary arrest, exo and endocytosis, the biochemical characterization of ciliary membrane components from wild type and mutant Tetrahymena, the development of techniques to stabilize the proteins in the apical membrane of the toad bladder, and the analyses of luminal vs. contraluminal membranes from rat renal cortex after separation by free flow electrophoresis.